AES E-Library

FM Direct Stereo Decoder

In the conventional FM stereo receiver an antibirdie noise filter is required to eliminate beat noise due to the harmonics of the switching signal and the adjacent broadcast signal. This filter causes deterioration in distortion and separation characteristics. It has been difficult to obtain a receiver having good anti-interference capability and high-fidelity sound at the same time. In the new system these problems are solved by switching the sinusoidal subcarrier directly with a pulse train which is derived from the FM signal.